The evolution of therapies for diseases associated with abnormal cell proliferation such as cancer has provided many choices in therapeutics agents for clinical treatment. To date, thousands of potential anticancer agents have been evaluated but the mainstay of treatments remains weighed down with complications and toxic side effects. Current therapeutic agents are categorized into six general groups: alkylating agents, antibiotic agents, antimetabolic agents, hormonal agents, plant-derived agents, and biologic agents. For a complete description of these agents, see U.S. Pat. No. 6,905,669.
Monoclonal antibody (“mAB”) drugs are a relatively new innovation in biologic agents used in cancer treatment. A monoclonal antibody is a laboratory-produced molecule that is designed to attach to specific cancer cells. A few examples of mAB treatment include: rituximab—for chronic lymphocytic leukemia and non-Hodgkin's lymphoma; gemtuzumab for certain types of acute myelogenous leukemia; cetuximab—for head, neck and colon cancer; and alentuzumab—for T cell leukemias and lymphomas. Although promising as a treatment for cancers, the use of mABs as a stand alone treatment has failed to meet expectations. Therefore, monoclonal antibodies are most often supplemented with the use of highly toxic chemotherapy and radiation therapy to improve the patient survival rate. Clearly a need still exists for more effective drug system and administration regimens for treating cancer in a relatively nontoxic and specific manner.